Some people have apparently been dumping their aquariums (fish and all) into the water across the province, and now those once-tiny pets are growing very, very large in the wild. We’re talking goldfish the size of dinner plates here:

These bloated…things have been appearing in ponds and streams from Lethbridge to Fort McMurray, and now officials think something is fishy.

“It really is becoming an issue,” Aquatic Invasive Species Co-Ordinator Kate Wilson says in the video above. “Once released from your small aquarium, a lot of these species can get quite large because they’re not constrained by the size of the tank.”

In other words, hungry-hungry goldfish are binge-eating all of the nutrients in these bodies of water, while simultaneously increasing competition for the few that remain. And since three dozen of these oversized fish were pulled from a storm pond all the way up in Fort McMurray last summer, we know even Canada’s notorious winters aren’t powerful enough to take them out.

The worst part? Fat fish populations are on the rise.

“We just really don’t want to see them breeding in the wild like this,” Wilson said.

It’s still unclear exactly what kind of impact the invasive goldfish are having, but officials assume it isn’t good. Anyone caught flushing live fish or the contents of their aquarium can be fined up to $100,000. Plus it’s pretty inhumane.

“It’s a really cruel thing to do to a pet,” Wilson said. “It will probably die a horrible death, but some of them are so robust that they will survive, and they will actually do potentially huge damage.”